Modeling subgrid scale mixture fraction variance in LES of evaporating spray
Modeling subgrid scale mixture fraction variance in LES of evaporating spray
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DOI：
10.1016/j.combustflame.2006.07.003
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发表时间：
2006-09-01
影响因子：
4.4
通讯作者：
Domingo, Pascale
中科院分区：
文献类型：
--
作者：
Pera, Cecile;Reveillon, Julien;Domingo, Pascale
本文对空间衰减均匀湍流中的稀液喷雾蒸发过程进行了数值模拟。采用欧拉描述的流动，而使用拉格朗日建模捕获的离散液相的行为。通过改变喷雾特性，对连续载流相的时间尺度和长度尺度进行了全面模拟，建立了喷雾载流相直接数值模拟（CP-DNS）数据库。然后，CP-DNS在粗网格上进行过滤，以对子网格规模（SGS）闭包进行先验测试。目的是提供近似的水平SGS混合分数的燃料喷雾湍流燃烧的大涡模拟（LES）方差的方法。直接估计的方差尺度解决LES首先讨论。然后，解决了一个平衡方程的求解得到的方差，封闭的标量耗散率和蒸汽源和混合分数之间的相关性。从结果中，一个程序耦合喷雾蒸发与SGS湍流燃烧模拟出现。(c)2006年由Elsevier Inc.出版代表燃烧研究所
Simulations of a dilute spray evaporating in spatially decaying homogeneous turbulence are performed. An Eulerian description of the flow is adopted, while the behavior of the discrete liquid phase is captured using Lagrangian modeling. Time and length scales of the continuous carrier phase are fully simulated and by varying the properties of the modeled spray, a database of spray carrier phase direct numerical simulation (CP-DNS) is obtained. The CP-DNS is then filtered on a coarse grid to conduct a priori tests of subgrid scale (SGS) closures. The objective is to provide methods for approximating the level of SGS mixture fraction variance in large eddy simulation (LES) of fuel spray turbulent combustion. Direct estimation of the variance from the scales resolved in LES is first discussed. Then, the solving of a balance equation to get the variance is addressed, with closures for the scalar dissipation rate and the correlation between vapor source and mixture fraction. From the results, a procedure to couple spray evaporation with SGS turbulent combustion modeling emerges. (c) 2006 Published by Elsevier Inc. on behalf of The Combustion Institute.